If you're lucky enough to live close to a Trader Joe's, I've got a quick and easy, low-calorie lunch suggestion for you. Provided I have the three simple components stocked, I eat this for lunch every damn day:
1 box Trader Joe's Creamy Corn and Roasted Red Pepper Soup
1 TJ's Spicy Jalapeño Chicken Sausage, chopped into tiny pieces
¾ cup TJ's frozen organic sweet corn
The chicken sausage is already cooked, so just toss all that in a saucepan, grind some black pepper in, warm it up, and you've got two meals' worth of healthy, filling soup—and for only about 300 calories and less than two bucks per serving. It also freezes and reheats beautifully.